Electric motor



Jan. 22, 1935. J P N '5- AL 1,989,021

' ELECTRIC MOTOR Filed 1934 2 Sheets-Sheet l Jan. 22, 1935.

J. PEDERSEN ET AL ELECTRIC MOTOR Filed Jan. 11, 1934 2 Sheets-Sheet 2 JizZzz; Zcle/sezz, %ar/J z Jflawil,

g I M4111 Patented Jan. 22, 1935 PATENT OFFICE ELECTRIC MOTOR Julius Peder-sen and Marvin I. Dowell,

Bridgeport, Conn.

Application January 11, 1934, Serial No. 106,277

GCIa-lms.

This invention relates to electric motors and has special reference to toy electric motors adapted to form motor means for toy boats and the like.

Such toy motors are necessarily greatly re stricted in size and require a very compact arrangement of the parts. Moreover, they must be capable of developing high torque in proportion to their size. Also they must be capable of effective operation from small batteries such as the batteries used in flash lights.

One important object of the invention is, therefore, to provide a motor of very small size and compact arrangement which will develop a high torque in proportion to its size.

A second important object of the invention is to provide a toy direct current motor which may be effectively operated from a miniature battery such as is used in a flash light.

In direct current motors it is necessary to employ a commutator and in the usual form of such devices it is diiiicult and expensive to manufacture a suitable commutator which shall have a size proportionate to the motor so that, in many small motors, the commutator is so large in proportion to the other parts that it utilizes an excessive part of the power developed to efiect its operation. 7

A third important object of the invention is to provide a novel and very simple form of commutator for toy motors.

Also, it is difiicult to install the usual type of motor in toys because of the trouble experienced in fitting it into proper position in a toy and there securing it.

A fourth important object "of the invention is to provide a novel form of toy motor so constructed that it may be assembled in a toy with extremely little manipulation.

with the above and other objects in view as will be hereinafter apparent, the invention consists in general of certain novel details of construction and combinations of parts hereinafter fully described, illustrated in the accompanying drawings and specifically claimed.

In the accomparwing drawings like characters of reference indicate like parts in the several views, and:

Figure 1 is a plan view of a toy boat and .motor constructed in accordance with this invention.

Figure 2 is a vertical section on the fore and aft center line of the boat.

Figure 3 is an enlarged section on the line 33 of Figure 2, but showing only a switch arrangement.

FigureiisasectiononthelineHofFigure 3.

Figure 5 is an enlarged side elevation of the motor shown in Figure 2 but at right angles to the showing in that figure.

Figure 6 is a section on the line 6-6 of Figure 5.

Figure 7 is a greatly enlarged face view of the commutator used herein and showing the brush.

Figure 8 is an edge view of this commutator also showing the brush.

Figure 9 is a side elevation of a second form of the motor showing the same arranged to constitute an outboard motor for a boat.

Figure 10 is a section on the line 10-10 of Figure 9.

Figure 11 is a side elevation of a third form of the motor.

Figure 12 is a section on the line 12-12 of Figure 11.

Figure 13 is a plan view of a six pole rotor adapted to be used in this type of motor.

Figure 14 is a side elevation of this six pole rotor.

Figure 15 is a view of a six contact commutator for use in connection with the six pole rotor.

, Figure 16 is a side view of a two pole rotor for use in a toy motor.

Figure 17 is a face view of the two pole rotor.

Figure 18 is a side elevation of a motor frame adapted to be used in connection with the form of motor shown in Figure 11.

Figure 19 shows a second form of motor frame suitable for use in the motor of Figure 9.

I Figure 20 shows a modification oi the frame arrangement shown in Figure 19.

Figure 21 shows a second modification of the motor frame of Figure 19.

Figure 22 shows a third modification of the motor frame of Figure 19.

In the form of the invention shown in Figures 1 to 8 the motor includes a frame of magnetic metal preferably bent or stamped to shape to provide a pair of parallel frame legs or poles 10 connected by a cross member or core 11 on which is a field winding 12. As shown in Figure 20 a wrapping 13 of insulating material surrounds this core so that the field winding, which is preferably of enameled wire, is safely insulated from 'the frame. A tie member 14 connects the free ends of the poles 10 and is made of some suitable non-magnetic material such as brass or the like. A long bearing tube 15 projects from the center of this tie member at right angles thereto and this long tube serves, as will be presently explained, not only as a hearing but also as the means for positioning the motor in a toy and pref erably acts as the sole securing means for the motor. A shaft 16 extends through this tube and projects from both ends thereof so that its inner end lies between the poles 10. On the inner end of this shaft is fixed the rotor or armature which, in this form, is made from a single stamping of magnetic metal having a disk like center 17 and four pole pieces 18 bent at right angles to the center and evenly spaced around said center. This rotor or armature has its poles of substantially equal width to the poles 10 and the spaces between the poles 18 are also about the same width as the poles 10. It is to be noted that the armature poles are located opposite the portions of the poles 10 where the magnetic field is most intense and thus a high torque in proportion to the size of the motor and its current consumption is developed.

The commutator consists of a square nut 19 of brass or other suitable conductive material against which rests a circular washer 20 of insulating material having a diameter less than the diagonal distance across the nut and greater than the distance between opposite flats of the nut. In other words, the diameter of the washer is intermediate the diameters of circles circumscribed about and inscribed in the square of the nut. By this construction, corners of the nut project slightly beyond the washer periphery while the periphery of the washer between said corners projects beyond the nut. A spring brush 21 is supported from the tie bar 14 but is insulated therefrom by an insulating strip 22. This brush is connected to one end of the winding 12 by a wire 23 and bears at its other end against the commutator, the brush being positioned, as in Figure 8, to engage both the washer 20 and the nut 19. Thus, the brush alternately rests on the washer out of contact with the nut and on the nut comers out of contact with the washer so that circuit through the winding is alternately open and closed. This commutator is mounted, in this form, on the shaft 16 within the cage formed by the poles 18 so that it cannot well be tampered with. The nut 19 is thus in conductive connection to the frame and if the remaining end of the winding 12 be connected to one terminal of a battery and the frame of the motor be connected to the remaining terminal of the battery the motor will operate.

In using the motor as means to drive a toy such as the boat B a hole 24 is drilled in a suitable part of the toy such as the bottom of the boat and this hole is of such size that the sleeve 15 will fit tightly therein. The position and direction of this hole is controlled by the elements to be actuated by. the motor. In this case the hole is drilled amidships toward the after end of the boat and inclines downwardly from front to rear. At 25 is a propeller having a hub sleeve 26 which fits tightly on the end of the shaft 16. This sleeve 26 may be made long enough to abut the sleeve 19 and prevent longitudinal movement of the shaft in the latter or a retaining washer 27 may be mounted on the shaft for the same purpose as in Figure 6.

Mounted in the hull of the boat or body of the toy is a trough like cradle having spring sides 28 proportioned and spaced to hold a battery 29 of the usual flash light type. This cradle is positioned forward of the motor and at the afterend of the cradle is a metallic stop member 30 to which the motor frame is grounded and which bears against the metallic bottom of the battery which forms one of the electrodes in a battery of this kind. The bottom of the cradle is turned up at its other end to form a standard 31 and to the after side of the lower part of this standard is pivoted a switch plate 32 against which the other electrode of the battery rests. Through this switch plate extends a metallic contact stud 33 constantly in engageable position with the standard31 and movable by movement of the switch plate into and out of alignment with the last mentioned electrode to close and open a circuit between said electrode and the metal cradle. A handle 34 is provided to manipulate the switch and the cradle is connected to the winding 12 by a wire 35. A housing 36 may, if desired, enclose the motor. By means of this arrangement the motor may bestopped or started at will.

In the form of the invention shown in 9, 10 and .19, the frame is identical with that previously described except that the tube 15 of the previous form is replaced by a tube 15a which is carried by the core 11 and the single or continuous winding 12 is replaced by a pair of windings 12a, one on each side of the tube 15a. In this form the armature is shown as consisting of a solid metal piece 17a having four projecting. pole pieces 18a preferably formed by milling, drop forging or the like mechanical operation. As before the shaft 16 supports this armature and also carries the square contact nut 19 and insulating washer 20 against which bears a spring contact 21a which is insulatedly supported from a pole 10, the insulation being shown at 22a. As here shown this modified motor is arranged to constitute an outboard motor for boats and to that end the core 11 carries a short tube 37 and a long tube 38, the short tube forming means by which the motor may be mounted on a gudgeon projecting from the stern of a toy boat. The long tube is offset at its lower end and carries a bearing tube 39 wherein is mounted a shaft 40 having on its forward end a bevel gear 41 which meshes with a bevel pinion 42 fixed on the lower end of the shaft 16. On the after end of the shaft 40 is mounted a propeller 25a.

In the form of the motor shown in Figures 11, 12 and 18 the frame is made from two stampings each having a core portion 1112 with poles 10b at its ends, the two portions being superposed to form a core for a pair of windings 12b. The tube 15b extends through the centers of these cores. Through the tube passes a shaft 1612 which, above and below the cores, carries a laminated armature 17b having four pole portions 18b, and on the shaft is mounted the usual square contact nut 19 and insulating washer 20 engaged by a spring contact 21a. insulated and supported as in the last form.

A modified form of the armature made from a single stamping is shown in Figures 13 and 14 and in this form the armature center 170 is provided with six arms having pole pieces 18c. Obviously, a somewhat different commutator must be used with this form and consequently the square nut is, as shown in Figure 15, replaced for this form by a hexagonal nut 19b cooperating with a washer 20b of a size to permit the points of the nut to project slightly as before while covering the remainder of said nut. A brush 21b is of course provided for this commutator.

In Figures 16 and 17 is shown a further modification of the armature in which but two poles 18d are carried by the armature center 17d.

In Figures 21 and 22 are shown modifications of the frame having in each case a central portion 11c with diverging arms 10c at its ends, windings being arranged on these arms adjacent the central portion 110. In Figure 21 the usual bearing tube is carried by the portion 110 while in Figure 22 a bearing tube 15d is supported by a tie member 140.

There has thus been provided a simple and efiicient device of the kind described and for the purpose specified.

Obviously the motor may be assembled from any desired selection of the parts here shown and many others but it is not considered either necessary nor practicable to attempt to illustrate the many variations which may be made in details and assembly of parts. It is to be understood, however, that the invention is not confined to these particular details and assembly but is only to be limited in accordance with the scope of the appended claims.

Having thus described the invention, what is claimed as new, is:

1. A motor for toys having a frame, and along tube extending from saidframe and adapted to fit an opening in a support to position the motor relative to the support and to constitute a bearing for a motor shaft.

2. A toy electric motor having a frame including field poles, a long tube extending from said frame and adapted to fit an opening in a support to position the motor relative to the support, a shaft journalled in said tube and extending therethrough at each end, one end of the shaft extending between the field poles, and an armature on the end of the shaft between said poles.

3. A toy electric motor having a frame including field poles, a long tube extending from said frame and adapted to fit an opening in a support to position the motor relative to the support, a shaft journalled insaid tube and extending therethrough at each end, one end of the shaft extending between the field poles, an armature on the end Of the shaft between said poles an h ing armature poles arranged to form a cage, and a commutator housed within said cage.

4. A motor for toys having a frame including a substantially U-shaped member of magnetic material having ends arranged to form field poles, field winding on said member intermediate said poles, a shaft supported by the frame to extend axially of the member between said field poles, an armature of magnetic material free from windings and carried by said shaft between said poles, said armature having a plurality of poles, a commutator grounded to the frame, and a brush-for the commutator conductively connected to one terminal of the field winding, the armature poles forming a cage and the commutator being located within said cage.

5. In a toy, a supporting structure having a hole extending from within outwardly, an electric motor having a frame provided with a bearing tube fitted tightly in the hole to secure the motor in place, said motor frame including field poles and a winding therefor and the motor including an armature and supporting shaft extending through the bearing tube, a driven element on the outer end of said shaft, and means to supply the field winding interruptedly with current.

6. In a toy, a supporting structure having a hole extending from within outwardly, an electric motor having a frame provided with a bearing tube fitted tightly in the hole to secure the motor in place, said motor frame including field poles and a winding therefor and the motor including an armature and supporting shaft extending through the bearing tube, a driven element on the outer end of said shaft, 9. commutator grounded to said frame, a brush conductively connected to one terminal of the winding and bearing on the commutator, a battery supported in said supporting structure with one terminal conductively connected to the frame, and means including a switch for conductively connecting the remaining terminals of the winding and battery.

JULIUS PEDERSEN. MARVIN J. DOWEIL. 

